Previous treatment for the Legg Calves Perthes disease usually consists of placing each leg of the patient in a cast, both legs held in abduction and internal rotation by a cross-bar extending between the two casts. This system immobilises the patient in a particular position for a long time. Due to the young age of the patients asnd the restlessness thereof associated with young age and the uncomfortable prospect of remaining several weeks in bed doing nothing, the treatment is often only partly applied and thus not fully successful. The reason for this unsuccessful treatment with conventional apparatuses is that the young patient will tend to voluntarily release relatively frequently the cross-bar from themselves, since it is physically possible for them to reach out to this cross-bar from their bed-laying condition. Indeed, the young patient, not being fully conscious at that age (usually around 10 years old) that for the treatment to be successful, constancy in the leg pulling action thereof during the several weeks long treatment period is a prerequisite.
Leg pulling apparatus are known such as the one described in U.S. Pat. No. 1,021,688 issued Mar. 26, 1912 entitled "LEG PULLING APPARATUS" by the inventor L. J. Le Jeune. This apparatus exerts an adjustable traction on the patient's legs but does not provide any abduction, namely drawing away from the median line of a bone or muscle from an adjacent part or limb.